1. Field of the Invention
The present invention relates to safe-and-arm or securing device for the fuze of a spinning or spin-stabilized projectile which includes a fuze member and a supporting member in which a spherical rotor is rotatably supported, and which has a radial groove formed therein. The rotor possesses a bore having a detonator inserted therein, and in a peripheral region incorporates a groove which extends along a plane which is axially offset relative to the radial groove, and with a spreadable or expandable restraining medium being inserted into the groove. The restraining medium releases the rotor which is retained in its secured position only subsequent to the firing of the projectile through the securing element which is spreadable and axially displaceable under the effect of axial and spin forces and which allows the rotor, after its release, to be pivoted in conjunction with the detonator into the armed position.
2. Discussion of the Prior Art
From the disclosure of German Laid-Open Patent Appln. 20 09 988 there is disclosed a rotor securing or safe-and-arm device for the fuze of a spin-stabilized projectile. For effectuating the arming thereof it is necessary to provide for a firing acceleration as well as for the spin. The forces which result therefrom are exerted against a U-shaped expandable restraining ring. The restraining ring is seated in an annular or ring-shaped recess in the rotor. The sliding plane for the restraining ring is of a castellated configuration in the direction extending towards the rotor center. As a consequence thereof, the restraining ring is adapted to assume a forward position which is offset relative to a radial groove facing towards a housing.
Malfunctions can be readily encountered as a result of the non-uniform or uneven weight distribution of the U-shaped restraining ring. The firing acceleration and the spin can tilt the restraining ring in the radial groove facing the housing to such an extent during the rearward and opening displacement, that the arms will hinder the rotor from assuming the spin which is necessary for the functioning.
Furthermore, during rough handling of the projectile, as a result of an unintentional impact the restraining ring can clamp or jam in its rearward position and arrest the rotor in the secured or safe position. In both instances there are then encountered highly-explosive duds subsequent to firing.
From the disclosure of German Pat. No. 25 39 750 it has become known, for a fuze of a spin-stabilized projectile, to provide a clamp-like securing element as the safe-and-arm or securing device for a rotor, and which is constituted of two radially curved arms which are interconnected through a curvilinear web or connector. The curvilinear or arched connector allows for a continual and uniform deflection of the two arms at a specified projectile spin. The action of the safe-and-arm device is only directed towards dependence upon the projectile spin. There is no provision of any arming criteria for the firing impulse.